Demography

Encyclopedia of Public Health
COPYRIGHT 2002 The Gale Group Inc.

DEMOGRAPHY

Demography is the study of the growth, change, and structure of the human population. Changes in a population's size and structure are caused by changes in the birthrate, the death rate, and the net migration rates. Demographic research focuses on why people have the number of children they do; on factors that affect death rates; and on the reasons for immigration, emigration, and geographic mobility. Understanding a society's demography is an essential tool in determining current and future public health needs.

HISTORY OF THE HUMAN POPULATION

The twentieth century was a very unusual period, demographically. World population grew at a more rapid and sustained pace than at any time in human history, as shown in Figure 1. The global population grew from approximately 1.7 billion people in 1900 to 6 billion in 1999. The annual population growth rate averaged 1.3 percent for the entire twentieth century, and was as high as 2.3 percent between 1965 and 1970. (A sustained 2.3 percent annual growth rate would have meant a doubling of the world's population in thirty years.)

By contrast, throughout most of history the human population grew very slowly. Occasionally, in some regions, there were periods of very rapid population growth—and also very rapid population decline. However, these periods generally averaged out over time, and overall population growth was extremely slow. For example, between the years 1 c.e. and 1750, the average annual population growth rate was only 0.06 percent. (At this rate, the population would double, on average, only once every 1,250 years.) A period of rapid population growth began around 1750 in Europe and North America. Rapid population growth in most other parts of the world began between 1920 and 1960.

Why did the population begin to grow rapidly first in Europe and North America, next in Japan,

Figure 1

Australia, and New Zealand, then in most of Asia and Latin America, and finally in Africa and the rest of the world? The answer lies in how a population grows or declines. A change in the size of a population occurs in only a few ways: Either births and immigrants add new members to the population, or deaths and emigrants remove members from the population. Throughout most of human history both birthtates and death rates were high, though birthrates were slightly higher than death rates on average. Slightly higher birthrates than death rates meant that the population was growing, although at a very slow rate. Migration added to some populations and subtracted from others at different periods in history.

Beginning in the eighteenth century, however, death rates began to decline, slowly at first and then more rapidly. For example, death rates declined from about 35 to 45 deaths per 1,000 population in the period from 1750 to 1850 to around 8 to 12 deaths per 1,000 in low-mortality countries (Europe, North America, Japan, and Australasia) in the late twentieth century. This decline began in different parts of the world at different times. In North America and Europe, the timing of the mortality decline was closely tied to the beginning of the Industrial Revolution. In Asia, Latin America, and Africa, declines in death rates took place mostly during the twentieth century. Declining death rates in combination with continuing high birthrates triggered the rapid growth of the population. Simply put, many more people were born into the population each year than left it through death.

Historical research shows that much of the mortality decline in Europe and North America occurred before most modern changes in medical technology and treatment, and therefore was caused by other factors. These factors include improvements in public health (including sanitation, waste disposal, clean water supply, and quarantine); changes in personal hygiene (including bathing, handwashing, and household cleanliness); improved standards of living (including better nutrition and housing); and improved political, economic, and transportation systems, which led to better responses to food shortages and drought.

These factors also played an important role in reducing death rates in Asia, Latin America, and Africa during the twentieth century. However, improvements in medical and public health technology were also important in these regions. For example, immunization programs, pesticide spraying against mosquitos that spread malaria and yellow fever; oral rehydration therapy for diarrhea; antibiotics; and improved and more widely available health care have all contributed to mortality reduction.

Despite continuing gains in health and survival, the pace of population growth began to slow in industrialized countries in the mid–twentieth century and in other regions of the world in the last three decades of the twentieth century. The reason is that birthrates began to decline. In some European countries, birthrates fell so low by the end of the twentieth century that their population growth rates became slightly negative, meaning that the number of people in these countries is declining slightly. For example, between 1995 and 2000, Italy had a birthrate of 9 per 1,000 population, or an average of about 1.2 births per woman. During this period, Italy's death rate was 10.4 per 1,000 population, so the Italian population became slightly smaller each year. Birthrates have also fallen to historically low levels in many countries in Asia and Latin America. There is also substantial evidence that birthrates are declining in many African countries as well. However, there is still great variability in birth and death rates among regions of the world, as the figures in Table 1 show.

The decline in birthrates is due to dramatic changes in economic and social conditions, ideas about the family and the role of children and women, the availability of family planning programs, and the acceptance and use of contraception. Although much of the fertility decline in

Table 1

Average Annual Birth Rates, Death Rates, Total Fertility Rates, and Life Expectancy for Regions of the World, 1995-2000

Birth Rate (per 1000 population)

Death Rate (per 1000 population)

Total Fertility Rate (Avg. Births per Woman)

Life Expactancy (Avg. Years of Life)

source: United Nations (1999) World Population Prospects: The 1998 Revision. Volume I: Comprehensive Tables. New York: Population Division, Dept. of Economic and Social Affairs, United Nations. ST/ESA/SER.A/177, Table A.1.

Europe and North America occurred before many modern contraceptive methods were available, the development and widespread use of contraceptive methods has played a major role in reducing fertility throughout the world. Contraceptive methods include the hormonal pill, the intrauterine device (IUD), sterilization (vasectomy for men and tubal ligation for women), hormonal injections and implants, and barrier methods such as condoms, spermicidal foam and jelly, diaphragms, and cervical caps. In some countries, such as the former Soviet Union and Japan, induced abortion has also played an important role in reducing the birthrate.

Even though birthrates have fallen substantially in many countries, their populations continue to grow because of the effects of their age structure, or "population momentum." For example, the U.S. population continued to grow at almost 1 percent per year during the 1980s and 1990s despite a very low birthrate. The reason is that a substantial proportion of the population was in their childbearing years because of the "baby boom" in the 1950s and early 1960s. The effects of population momentum is temporary: In the absence of immigration, if birthrates remain low for the next fifty years, the size of the U.S. population will begin to decline. However, immigration is likely to continue during this period, keeping the U.S. population growing at a relatively slow pace.

MEASURING POPULATION CHANGE

Demographers use several standard ways to measure population processes. Birthrates and death rates are the two most important measures. A birthrate (also called a crude birth rate) is the number of births in a given place and year per 1,000 population:

Similarly, the death rate (also called a crude death rate) is the number of deaths in a given place and year per 1,000 population:

The birthrate and death rate for the United States between 1995 and 2000 were 14 births per 1,000 population and 8.5 deaths per 1,000 population.

In a population with no immigration or emigration, the population growth rate is simply the birthrate minus the death rate divided by 10. By convention, population growth rates are expressed in percent (that is, per hundred people) rather than per thousand people. In the United States, the annual population growth rate (which was 0.83 percent for the years 1995 to 2000) is higher than the difference between the birthrates and death rates, because of immigration. In fact, immigration accounted for approximately one-third of the annual growth rate in the United States between 1995 and 2000.

Two other indices are commonly used to measure population change. The Total Fertility Rate (TFR) measures the average number of children that women would have in their lifetime if birthrates remain at current rates in the future. Between 1995 and 2000 the TFR ranged from 1.2 children per woman in Italy to 7.1 children per woman in Uganda. Life expectancy measures the average number of years that people would live if death rates remain at the current in the future. Table 1 shows that the TFR and life expectancy varied substantially among different regions in the world between 1995 and 2000.

At the start of the twenty-first century, the population of the United States indicates historically low birthrates and death rates and relatively slow population growth. The U.S. average annual population growth rate was 0.83 percent between 1995 and 2000. About two-thirds of this growth rate is accounted for by more births than deaths in the United States each year. About one-third is due to the presence of more immigrants than emigrants each year.

A major influence on the U.S. population in 2000 is the "baby boom" that took place between approximately 1948 and 1965. Birthrates rose substantially in the United States during this period because many couples postponed having children during the Great Depression in the 1930s and during World War II. These couples began to have children at the same time as younger couples who were just getting married. Another reason for the baby boom was the good economic climate conditions during the 1950s, which meant that couples could afford to have more children. Demographers use the term "cohort" to mean all people who were born during a particular year. The cohorts born during the baby boom were much larger than the cohorts born in previous years. Because of the larger cohorts during the baby boom, hospital maternity wards were overcrowded and demand for obstetric and pediatric health services rose substantially. As the baby boom cohorts got older, elementary schools, then high schools, and then colleges bulged at the seams as they tried to cope with a sudden increase in the number of students.

As the baby boom cohorts began to enter their childbearing years (conventionally defined as 15 to 49 years of age for women), they had much lower fertility rates than their parents. For example, the Total Fertility Rate for women during the baby boom years 1955 and 1960 averaged 3.7 children per woman. Women born during the baby boom who were having their children between 1985 and 1990 averaged only 1.9 children per woman. However, because the baby boomers were a large proportion of the U.S. population, the number of births actually rose between 1985 and 1995 compared with earlier years. This is the process of population momentum, described above. The United States has an unusual age structure as a result of the baby boom. Because of this age structure, the U.S. population will continue to grow for several more decades even if fertility rates remain low.

The baby boom will continue to have another major impact on the demography of the United States in the next several decades—baby boomers will contribute to the aging of the population. People born at the beginning of the baby boom are just beginning to approach retirement age in 2000. Between 2010 and 2030, most people in the baby boom cohorts will reach age 65. America's population will continue to grow older, on average, because of the aging of the baby boom cohorts. Another reason that Americans will be older on average is that fertility and death rates are low. That means that a smaller proportion of the population are young children, and therefore, that a larger proportion of the population are older adults. It also means that people are living longer lives, on average, than in the past.

The aging of the U.S. population has been gradual during the last quarter of the twentieth century. In 1975, 10.5 percent of the population was age 65 and older. By 2000, this figure had grown only to 12.5 percent, a relatively modest increase. However, by 2025, almost 19 percent will be age 65 and older, and by 2050 the figure will be almost one-quarter of the population. Undoubtedly, the aging of the population means that the health needs and problems of older Americans will become an increasingly important focus for public health policy in the early twenty-first century.

Another major demographic trend in the United States is immigration. The United States is a country of immigration. Almost all Americans are descended from immigrants to North America. Even Native Americans, who preceded European and African settlers by many centuries, are believed to have immigrated to North America from Asia. The volume of immigration to the United States has been increasing since the 1950s. Between 1992 and 1999, an average of 800,000 immigrants were legally admitted to the United States every year. This number includes family members of U.S. citizens and residents, as well as refugees, highly skilled workers, and farm workers and lower-skilled workers. An additional 250,000 immigrants probably entered the United States illegally during the same period. Approximately 220,000 people were estimated to emigrate (that is, to move to other countries) each year in the late 1990s.

Between the beginning of European settlement in the 1600s and the Civil War, most immigrants came from northern and western Europe or (generally as slaves) from Africa. Between 1880 and 1914, there was a major wave of immigration to the United States. In 1914, approximately 1.2 million immigrants were admitted, a number which far exceeds the average annual number of legal immigrants in the late 1990s. Although most immigrants arriving during this period continued to come from northern and western Europe, a substantial proportion came from southern and eastern Europe and from Asia.

Among immigrants arriving legally in the 1990s, approximately half came from Latin America, 30 percent from Asia, and 13 percent from Europe. Just as earlier waves of immigration molded the ethnic composition of the United States, recent immigration patterns have contributed to the current ethnic makeup as well. However, other factors have also had an important effect on ethnic composition at the end of the twentieth century, including intermarriage among couples of different ethnic backgrounds and small but significant differences in fertility rates between ethnic groups. In 2000, approximately 72 percent of Americans were white non-Hispanics, 12 percent were African American, 11 percent were Hispanic, 4 percent were Asian, and 1 percent were Native American. The U.S. Census Bureau estimates that by 2025 about 62 percent of the population will be non-Hispanics whites, 13 percent African America, 18 percent Hispanic, 6 percent Asian, and 1 percent Native American. Many Americans have multiple ethnic backgrounds, however, and cannot be classified easily into a single ethnic category. For this reason, the United States 2000 Census allowed people to classify themselves in more than one ethnic group. Estimates of the future ethnic composition of the United States have to realize that classification by a single ethnic origin is likely to be less useful in the future.

DEMOGRAPHY AND PUBLIC HEALTH NEEDS

Understanding a society's demography is an essential tool in determining current and future public health needs. Demographic structure can affect public health needs in at least three ways: (1) age structure and sex ratio affect the types of health problems encountered, (2) population growth rates affect future needs for health care delivery, and (3) the existence of substantial immigrant and refugee populations can also be important.

The health needs of a population differ considerably by age and by sex. A population's history of birth and death rates changes the age structure in a way that is easy to predict. Generally, a fertility decline reduces the proportion of children in a population, while a decline in death rates increases life expectancy and the proportion of elderly in the population.

The United States provides a good illustration. During the baby boom period the age structure of the population was relatively "young" because birthrates were fairly high. A major emphasis of health care policy during that period was on prenatal and maternity care and on the health problems of mothers and children. In countries with even higher fertility rates, such as many African and some Asian countries, maternal and child health needs are even more of a priority because the proportion of the population at younger ages is even higher. During the last decades of the twentieth century, the population of the United States became older, on average. By 2025, a substantial and growing portion of the American population will be 65 and older. Therefore, health policy is increasingly being focused on the needs of the elderly.

The sex ratio can also affect health care needs. For most age groups, the sex ratio (that is the ratio of males to females) is close to equal. In general, however, men have higher death rates than women. As a result, at older ages sex ratios are generally much lower. That is, there are many fewer men than women. While women are likely to have longer life spans than men, they are also more likely to become widows and to have to care for themselves at older ages.

Population growth rates can affect the size and rate of growth in health care needs in a population. Specifically, provision of health services to a rapidly growing population is more difficult than to a population growing more slowly. In the United States, most policymakers seek to increase access to health services among the poor and underserved

Table 2

Example of the Effects of Population Growth on the Demand for Health Services

Country A

Country B

source: Courtesy of author.

1990 Total Population

1,000,000

1,000,000

No. of People Covered by Health Services in 1990 (25%)

250,000

250,000

Annual Population Growth Rate

3.0%

1.5%

1995 Total Population

1,161,834

1,077,884

No. of people covered in 1995 if 25% coverage is maintained

290,459

269,471

No. of people covered in 1995 if target of 35% coverage is met

406,641

377,260

segments of the population. In developing countries, policymakers are even more concerned with expanding access to health services. Rapid population growth can make it difficult to continue to provide the same level of services to all segments of the population, and even harder to increase the level of health services available.

Consider two relatively poor countries, both of which have exactly 1 million people in 1990, as shown in Table 2. In 1990, each country is providing health services to 25 percent of the population, or 250,000 people, and each country has a goal of extending health care to cover 35 percent of the population by 1995. If Country A is growing at 3 percent per year and Country B is growing at 1.5 percent, Country A is going to have a harder time both maintaining 25 percent health-service coverage and expanding its health services to cover 35 percent of the population.

To maintain health care coverage at a level of 25 percent, both countries will have to expand the number of people covered between 1990 and 1995 by training more personnel, building more facilities, and investing more in supplies and equipment. However, as Table 2 shows, Country B will have to cover only 19,471 more people in 1995 while Country A will have to cover an additional 40,459 people in order to maintain 25 percent coverage. To increase coverage to 35 percent, Country B will have to provide services to an additional 127,260 people while Country A will have to cover an additional 156,641 people. As this example shows, health planners need to take population growth rates into account when estimating the future health care needs of a population. The United Nations Population Division and the United States Census Bureau regularly produce population projections which can be used as guides to the likely future size and structure of a country's or local area's population.

With improvements in transportation and changing political and economic circumstances, immigration and emigration will be an important issue for the United States, and for most of the countries of the world, in the twenty-first century. Governments and international organizations generally divide immigrants into two groups: refugees, who are those fleeing their home countries because of political persecution or war; and labor or economic migrants, who go to other countries seeking employment and a better life. Refugees and economic migrants can move between two countries or within a single country. Note that the distinction between refugees and economic migrants is often not very clear. For example, migrants from a country facing severe drought may be fleeing to seek better economic opportunities and/or because they may face starvation and violence due to drought if they remain at home.

Immigrant populations, and particularly refugees, often pose important challenges for health planners and health-service providers. For example, recent immigrants may have little knowledge of the health care system or health and social-service providers. They often arrive with a different set of health beliefs and they may face language and cultural barriers when seeking health care. Recent immigrants are also likely to have lower incomes and to be more vulnerable to downturns in economic conditions such as recessions. Although immigrants in established migration streams usually have a network of social and family contacts in the country then migrate to, recent migrants often live closer to the margin than long-term immigrant groups.

Refugees often have additional health problems because of the political persecution they have faced. Their special health needs may include psychological treatment for conditions such as post-traumatic stress disorder and depression, as well as treatment for infectious diseases, injuries, and malnutrition. Refugees, like other immigrants, may also face discrimination in employment or in access to health and social services in the country they migrate to, which is likely to affect their health status.

While many refugees settle in the United States or other industrialized countries, the majority (more than 80%) find asylum in developing countries in Africa, Asia, and Latin America, where health services are often poor. Refugees often face serious barriers to finding employment in countries of asylum for two reasons: (1) farm land is not readily available to outsiders, especially those without funds to purchase land, and (2) few jobs exist in other sectors of the economy. As a result, they can become dependent on international aid organizations for economic support, food aid, and health services. Examples of this situation during the 1990s include Cambodian refugee camps on the Thai-Cambodian border, Ethiopian refugees in Sudan and Somalia, Somalian refugees in Kenya, and Guatemalan and El Salvadoran refugees in Mexico.

Anne R. Pebley

(see also: Behavior; Birthrate; Contraception; Family Planning Immigration; Life Expectancy and Life Tables; Planning for Public Health; Population Forecasts; Population Growth; Population Policies; Population Pyramid )

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Demography

Encyclopedia of Russian History
COPYRIGHT 2004 The Gale Group Inc.

DEMOGRAPHY

The demography of Russia has influenced, and been influenced by, historical events. Demographic shifts can be seen in the population pyramid of 2002. The imbalance at the top of the chart indicates many more women live to older ages than men. The small numbers aged 55-59 represents the drastic declines in fertility from Soviet population catastrophes during the 1930s and 1940s, followed by a postwar baby boom aged 40-55. The relatively smaller number of men and women aged 30-34 reflects the echo of the 55–59 year old cohort. The larger cohorts at younger ages reflect the echo effect of Soviet baby boomers. The Russian population pyramid is unique in its dramatic variation in cohort

Table 1

size, and illustrates how population has influenced, and been influenced by, historical events.

Trends in migration, fertility, morbidity and mortality shaped Russia's growth rate, changed the distribution of population resources, and altered the ethnic and linguistic structure of the population. The implications of demographic change varied by the historical period in which it occurred, generated different effects between individuals of different age groups, and influenced some birth cohorts more than others. Throughout Russia's history, demographic trends were largely determined by global pandemics, governmental policies and interventions, economic development, public health practices, and severe population shocks associated with war and famine.

As in other countries, population trends provided a clear window into social stratification within Russia, as improvements in public health tended to be concentrated among elites, leaving the poor more susceptible to illness, uncontrolled fertility, and shorter life spans.

Two unique aspects concerning Russia's demographic history warrant note. During both the Imperial and Soviet periods, demographic data were manipulated to serve the ideological needs of the state. Second, Russia's demographic profile during the 1990s raised questions concerning the permanence of the epidemiological transition (of high mortality and deaths by infectious disease to low mortality and deaths by degenerative disease). Life expectancies fell dramatically and infectious diseases re-emerged during the 1990s as demographic concerns became significant security issues.

sources of demographic data

The Mongols instituted the first population registry in Russia, but few large-scale repositories of demographic information existed before the late Imperial period. Regional land registry (cadastral ) records provided household size information and could be used with church records, tax assessment documents, serf work assignments, and urban hospital records to provide indirect and localized estimates of population, and in some cases, family formation, fertility, and mortality data. In 1718, the focus of enumeration shifted to an enumeration of individuals, with adjustments or revizy, conducted for verification. The move to local self-government, and the creation of zemstvos in 1864, also provided a wealth of historical data, particularly regarding the demographic situation within peasant households, but as previous sources, the data were limited to small scale regional indicators. In 1897, across the entire Russian Empire a population census with 100,000 enumerators collected information from 127 million present (nalichnoye ) and permanent (postoyannoye ) residents on residence, social class, language (but not ethnicity), occupation, literacy, and religion. A second census was planned but not executed due to the outbreak of World War I.

Enumeration and registration of the population was a serious concern in the Soviet period, and censuses of the population supplied important verification of residence, linguistic identity, and ethnic composition. The first comprehensive census in 1926 enumerated 147 million residents of the Soviet Union, 92.7 million of whom resided in the RSFSR. The next full census of 1939 was not published, due to political concerns. Subsequent postwar censuses in the Soviet Union (1959, 1970, 1979, 1989) improved significantly upon previous censuses in terms of quality of coverage. These data provided information that could be evaluated with increasingly comprehensive records on fertility, mortality, migration, and public health indicators collected through various state ministries at the allunion and republic levels.

During the post-Soviet period, scholars agree the quality of population information declined during the early 1990s, as state ministries reorganized, funding for statistical offices became erratic, and decentralization increased burdens for record keeping for individual oblasts. A micro census was carried out in 1994 of a 5 percent population sample. After false starts in 1999 and 2001 and heated debates over questionnaire content, the first post-Soviet census was conducted in October of 2002.

demographic trends in the russian empire

During the Time of Troubles (1598–1613), Russia experienced a sharp population decline due to declines in mortality and fertility. During the 1600s Russia's population increased, but the rate and stability of the trend over the century is subject to debate. During the following century substantial efforts to address public health needs were made in Russia's urban areas. Catherine II (the Great) established the first medical administration during the later 1700s, leading to some of the earliest epidemiological records for Russia. During the nineteenth century, mortality rates across age groups were higher than those found in Europe. Infant mortality was problematically high, declining only during the late 1800s due to increased public health campaigns.

Social changes such as the reforms of the 1860s served as catalysts for improved living standards, particularly in rural areas. These in turn improved the population's health. At the same time increases in literacy also improved health practices. Education and improvements in literacy across the empire led to linguistic Russification with members of various ethnic groups identifying primarily with Russian language. The positive influence of improved social conditions on demographic trends was checked by persistently unreliable food production and distribution, leading to widespread famines throughout the imperial period, but most notably in 1890. At the century's close, increased population density, particularly in urban areas, and extremely poor public works infrastructural provided an excellent breeding ground for deadly outbreaks of infectious diseases such as influenza, cholera, tuberculosis, and typhoid. Deaths from infectious diseases were higher in Russia than Europe during the early 1890s. Voluntary Public Health Commissions operated in the last decades of imperial rule. Lacking official state financial support, the commissions were unable to improve the health of the lower classes living in conditions conducive to disease transmission.

The state monitored the collection and dissemination of demographic information throughout the Imperial period. Records indicate that urban population counts, estimated deaths due to infectious disease, and population declines related to famines were, in some cases, corrected in three specific ways in order to minimize negative interpretations of living conditions within Russia and to avoid possible public unrest. First, information was simply not collected or published. In the case of fertility and mortality statistics this avenue was easily followed as most births and deaths took place at home and were not always registered. Secondly, selected information was published for small scale populations who tended to exhibit better health and survival profiles than the population at large. Focusing upon epidemiological records from large urban hospitals, imperial estimates tend to undercount the health profiles among rural residents and the very poor, which tend to be far worse than those with access to formal urban care. Lastly, records may have been generated, but not published. This appears to be the case in several analyses of the 1890 famine and cholera outbreaks in southern Russian during the 1800s. Rather than utilizing demographic information to assist the development of informed social policy, scholars conclude that national demographic information was often manipulated in order to achieve specific ideological goals.

demographic trends during the soviet era

The early years of Soviet rule were marked by widespread popular unrest, food shortages, civil war, and massive migration movements. The catastrophic effects of World War I, a global influenza epidemic, political and economic upheavals, and a civil war led to steep increases in mortality, declines in fertility, and deteriorations in overall population health. Between 1920 and 1922, famine combined with cholera and typhus outbreaks evoked a severe population crisis. As Soviet power solidified, several policies were enacted in the public health area, specifically in the realm of maternal and child health. Though underfunded, in combination with the expansion of primary medical care through feldshers (basic medical personnel), these programs were associated with declines in infant mortality, increased medical access, and improved population health into the 1930s.

During the late 1920s food instability reappeared in the Soviet Union, followed by a brutal collectivization of agriculture during the early 1930s. Millions of citizens of the Soviet Union perished in the collectivization drive and the famine that followed. Additional population losses occurred as a result of the Stalinist repression campaigns, as mortality was extremely high among the nearly fifteen million individuals sent to forced labor camps during the 1930s, and among the numerous ethnic groups subject to forced deportation and resettlement. These population losses were accelerated by massive civilian and military casualties during World War II. While each of these events is significant in its own right, in combination they produced a catastrophic loss of population that significantly influenced the age structure of the Russian Federation for decades to come. The population loss consisted of not only those who perished, but also the precipitous declines in fertility in the period, in spite of intense pro-natalist efforts. The precise population loss associated with this series of events is a subject of intense and emotional debate, with estimates of population loss ranging from 12 to nearly 40 million. Even individuals surviving this tumultuous period were affected. Those in their infancy or early childhood during the period exhibited compromised health throughout their lives as a result of the severe deprivation of the period. Even after the end of the war, economic instability and intense shortages exacted a significant toll on living standards, fertility, and health during the 1950s.

The 1959 census documented increasing population growth, improvements in life expectancy, and increases in fertility across Russia. Life expectancy increased to sixty-eight years by 1959, twenty-six years longer than the life expectancy reported in 1926 (forty-two). The total fertility rate in 1956 stood at 2.63, a marked increase from the 1940s. Urbanization increased the proportion of the population with access to modern water and sewer systems, and formal medical care. The following decades were periods of economic stability, improving living standards, expanded social services, improved health and decreased infectious disease prevalence. While overall fertility rates declined, population growth was positive and noticeable improvements were reported for infant and maternal mortality in Russia.

During the late socialist period, improvements in population health stalled, as Russia entered a period of economic and social stagnation. Increased educational and employment opportunities for women, combined with housing shortages and the need for dual income earners in each family, drove fertility below replacement levels by 1970. Life expectancy, which peaked in 1961 at 63.78 for men and 72.35 for women, declined during the 1970s for both sexes. Negative health behaviors such as smoking and drinking appeared to rise throughout the 1970s and early 1980s, and some reports of outbreaks of cholera and typhus were reported, especially in the southern and eastern regions of the country. Official statistics indicate an improvement in all demographic indicators in the mid-1980s, and links to pro-family policies and a strict anti-alcohol campaign could be drawn, but improved mortality and increased fertility were short-lived. By the late 1980s increased mortality among males of working age was observed.

The Soviet state also manipulated demographic data to serve ideological ends. At best, official publications regarding issues such as life expectancy were often overly optimistic. At worst, the compilation of standard indicators (such as infant mortality rates) was altered to improve the relative standing of the Soviet Union in comparison to capitalist countries. Most significantly, demographic information was withheld from publication, and sometimes not collected. In spite of achieving remarkable improvements in public health and high rates of population growth in decades after World War II, as its predecessor, employed population information to further its ideology as well as to inform policy development.

demographic trends during the post-soviet era

The post-Soviet era is marked by dire demographic trends. Rapid and wide scale increases in mortality and marked declines in already low fertility and marriage rates generated negative natural rates of increase throughout the 1990s. Population decline was avoided only due to substantial immigration from other successor states during the period. This period has been identified as the most dramatic peacetime demographic collapse ever observed. Aspects of the crisis are linked to long-term processes begun in the Soviet period, but were significantly exacerbated by economic and institutional instability of the later period.

Increasing male mortality, especially among older working-aged males, gained momentum during the 1990s. Estimates vary, but official estimates reported a six-year decline in male life expectancy between 1985 and 1995. Female life expectancy also declined, however more modestly. Deaths from lung cancer, accidents, suicide, poisoning, and other causes related to alcohol consumption underpin the change in mortality, but death rates for heart disease and cancer also increased. Period explanations focus on the stress generated by the economic transition, linking that stress to the mortality increase. Age effect models argue that men at these ages are somehow uniquely susceptible to stress. Cohort explanations point out that men in the later working ages (50–59) in 1990 represent the birth cohorts of 1940s, and the declining mortality of the 1990s is an echo of the deprivations of the post World War II period. Each explanation contributed to explaining the mortality increase, which took place amidst health care and infrastructural collapse.

The Soviet system of health care was very successful in improving public health during the early years of the regime, and during the initial period after World War II, however the distribution and organization of care led to diminishing return in the later years of the regime and the organizational structure proved ineffective in the post-Soviet period. During the 1990s financial crises lead to serious shortages of medical supplies, wage arrears in the governmental health sector, and the rise of private pay clinics and pharmacies. Increased poverty rates, especially among the growing pension aged population, precluded health care access. Public works (hospitals, prisons, sewer systems, etc.) were poorly maintained during the late Soviet era, and contributed to the resurgence of old health risks such as cholera, typhus, and drug resistant forms of tuberculosis during the 1990s. The reemergence of infectious disease shocked demographers and epidemiologists, who previously contended improvements in mortality were permanent, and that deaths infectious diseases were a unique characteristic of undeveloped societies. The resurgence of infectious diseases includes HIV/AIDS. The numbers of infected were low, but in 2003 HIV infection rates were projected to increase in the near future.

Russia's post-Soviet demographic crises generated concerns over declining population size, especially in the Far East where border security is a concern. Immigration helped maintain population size without shifting the ethnic composition, but anti-immigrant sentiments were strong during the late 1990s. In 2002 government attention had turned to below replacement fertility, but as in the rest of Europe the fertility rate remained very low. During the second decade after Soviet rule, demographic trends were cause for serious concern, but indicators, if not political attitudes, were stabilized.

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Demography

Demography

Demography is the scientific study of the size, composition, and distribution of human populations, and their changes resulting from fertility, mortality, and migration. Demography is concerned with how large (or small) populations are, that is, their size; how the populations are composed according to age, sex, race, marital status, and other characteristics, that is, their composition; and how populations are distributed in physical space (e.g., how urban and rural they are), that is, their spatial distribution (Bogue 1969). Demography is also interested in the changes over time in the size, composition, and distribution of human populations, and how these result from the processes of fertility, mortality, and migration.

The term demography is from the Greek demos (population) and graphia (writing). It is believed to have first appeared in print in 1855 in the book Elements of Human Statistics or Comparative Demography by the Belgian statistician Achille Guillard (1799–1876) (Borrie 1973, p. 75; Rowland 2003, p. 16).

Some demographers argue that demography is best treated as a subdiscipline or specialization of sociology owing to its organizational relationship with sociology (Moore 1959, p. 833). However, the organizational affinity in universities between demography and sociology is not universal. In some Eastern European universities, demography is organizationally linked with economics, and in some Western European universities, with geography. In many countries (e.g., China), demography is taught in a separate university department.

The American sociologist Kingsley Davis (1908–1997), who served at different times as president of both the Population Association of America and the American Sociological Association, wrote in 1948 in his classic sociology textbook, Human Society, that “the science of population, sometimes called demography, represents a fundamental approach to the understanding of human society” (1948, p. 551). The relationship between sociology and demography is hence a fundamental one: “Society is both a necessary and sufficient cause of population trends” (1948, pp. 553–554).

There are only two ways to enter a population, by birth and by in-migration. There are two ways to leave a population, by death and by out-migration. Thus, a population is often defined by demographers according to the specific needs of the research and researcher. Samuel Preston and his colleagues have written that the “term ‘population’ refers to a collection of items, for example, balls in an urn. Demographers use the term in a similar way to denote a collection of persons alive at a specified point in time who meet certain criteria” (2001, p 1). For example, the population of interest may be that of students attending a specific university during a specific year. In this situation, the students are born (i.e., enter) into the population when they enroll, and they die (i.e., leave) when they graduate.

Generally, demographers use vital registration (birth and death) records to count births and deaths in a population to determine fertility and mortality rates. The more difficult demographic process to measure is migration because in most countries registration records are not maintained when persons migrate into or out of the population. Data gathered around the world from decennial census and sample surveys are also used by demographers to examine demographic and sociodemographic issues.

Demographic techniques allow for the calculation of population projections, which specify the future size of the population by utilizing specific assumptions about the parameters driving the future fertility, mortality, and migration of the population. Population projections for all the countries around the world are periodically calculated by demographers at the United Nations and other international organizations and are made publicly available. Such projections are often used by government agencies and private firms to plan the infrastructure of cities, such as the number of schools, hospitals, airports, and parks that would be needed in the future in order for the cities to be able to function properly.

Demography is concerned not only with the observation and description of the size, composition, and spatial distribution of human populations and the changes resulting from fertility, mortality, and migration. Demography is also concerned with developing explanations for why the demographic variables operate and change in the ways they do: That is, why do some populations increase in size and others decrease? Why do some become older and others become younger? Why are some more urban and others more rural?

One paradigm in demography, known as formal demography, uses only demographic variables, such as age and sex, as independent variables to answer the above questions. Another paradigm, known as social demography, uses such nondemographic variables as marital status, race, education, socioeconomic status, occupation, household size, and type of place of residence—variables drawn mainly from sociology, economics, psychology, geography, anthropology, biology, and other disciplines—to answer the questions.

To illustrate, formal demographers might address differences in populations in their birth rates and death rates by considering their differences in age composition or in sex composition. Younger populations typically have higher birth rates than older populations; and populations with more females than males will usually have lower death rates than populations with more males than females (Poston 2005). Social demographers might address the above differences in populations in their birth rates and death rates by examining differences among them in, say, their socioeconomic status. Usually, populations with high socioeconomic status will have lower birth rates and death rates than populations with low socioeconomic status.

Demographic data may be introduced to provide some perspective for distinguishing between these two approaches. Human populations have different levels of fertility. Countries thus differ with respect to their total fertility rates (roughly defined as the average number of children born to a woman during her childbearing years). In 2004 Poland and Romania had very low fertility rates of 1.2, among the lowest in the world. Conversely, Niger, Guinea-Bissau, and Yemen had very high fertility rates of 8.0, 7.1, and 7.0, respectively—the highest in the world (Population Reference Bureau, 2004). Why do these fertility differences exist? Why do Niger, Guinea-Bissau, and Yemen have fertility rates that are so much higher than those of Poland and Romania? To answer this question, the social demographer would go beyond purely demographic issues of age and sex composition and would focus on the processes of industrialization and modernization.

Another example focuses on what demographers refer to as the percentage rate of natural increase/decrease, that is, the difference between the birth rate and the death rate. In 2004 both Russia and Bulgaria had a rate of -0.6 percent: that is, the difference between their crude birth and death rates was about -6/1000 or -0.6/100. In contrast, the rate in both Madagascar and Saudi Arabia was 3.0 percent. In these countries, the difference between their birth and death rates was 30/1000 or 3/100.

Why are these four countries growing at such drastically different rates? Why do Russia and Bulgaria have negative growth rates, and why do Madagascar and Saudi Arabia have positive rates? The formal demographer might develop an answer by considering the birth rates of these countries. The numbers of babies born per 1,000 population in 2004 in Russia, Bulgaria, Madagascar, and Saudi Arabia were 10, 10, 43, and 32, respectively. The latter two countries have higher rates of growth than the former two countries because their birth rates are so much higher. The social demographer would first consider the birth rate differentials, but would then go beyond this demographic consideration to an answer involving nondemographic factors that may be influencing the birth rates. Perhaps the economy has something to do with it (poorer countries have higher birth rates). Perhaps the level of industrialization of the country has an impact (the more industrialized countries generally have lower birth rates). Perhaps the role of women compared to men is having an effect (countries with more gender equity tend to have lower birth rates).

Whatever the reasons, the social demographer extends the answer beyond demographic reasons. Social demography is broader in scope and orientation than formal demography. Preston has noted, for example, that demography includes “research of any disciplinary stripe on the causes and consequences of population change” (1993, p. 593).

Given the impact of industrialization in the reduction of fertility and mortality and the international migration flows from less developed to more developed countries around the world, it is a common practice among demographers to observe separately the demographic processes in less developed countries from those in more developed countries. The issues that concern demographers often vary depending on the level of industrialization of each country. In less developed countries, high levels of fertility, high levels of infant mortality, a high prevalence of HIV/AIDS, and high levels of out-migration to more developed countries tend to be some of the main demographic concerns. In more developed countries, low fertility patterns, women having babies at later ages, populations with below replacement levels of fertility, and large numbers of migrants from less developed countries are some of the main issues being examined by demographers.

A frequent concern in demography is the extent to which changes in individual-level behavior have an effect on aggregate processes (Preston et al. 2001). For example, if it suddenly became normative for individuals in a population to become smokers once they reach a certain age, then the demographer would want to find out to what extent the life expectancy at age x would be affected, as well as the death rate for that population. Similarly, regarding fertility, if women in a certain country decided to have children at older ages, then the concern becomes to what extent such behavior can have an effect on the total fertility rate, on the growth rate, and on whether the population will be maintained at a replacement level of fertility (which in populations with low levels of mortality is around 2.1 children per woman).

Demographers also are often concerned with how social policy could impact the aggregate population processes. In China, for example, demographers have identified a relationship between the enforcement of fertility policies and increasing levels of social and economic development and the sex ratio at birth (Poston et al. 1997; Poston and Glover 2005). The sex ratio at birth is the number of males born per 100 females born and is around 105 in most societies. Since the 1980s in China it has been significantly above 105. In 2000 China’s sex ratio at birth was near 120. The rapid reduction of fertility in China, along with the long-standing preference for sons, has led to the selective abortion of female fetuses, and a sex ratio at birth above normal levels. As a consequence, in China there will not be enough women in the population for the next few decades for Chinese men to marry. This is a major effect of societal modernization and fertility-control policies (Poston and Morrison 2005).

Demographers do not always agree about the boundaries and restrictions of their field. John Caldwell stated the problem succinctly: “What demography is and what demographers should be confined to doing remains a difficult area in terms not only of the scope of professional interests, but also of the coverage aimed at in the syllabuses for students and in what is acceptable for journals in the field” (1996, p. 305).

Other demographers argue for a broader approach, noting that demography is not a specialization of sociology, or of any discipline, but a discipline in its own right. Consider the definition of demography in the popular demography textbook Population: An Introduction to Concepts and Issues by John Weeks: Demography is “concerned with virtually everything that influences, or can be influenced by” population size, distribution, processes, structures, or characteristics (2005, p. 5).

It is no wonder that J. Mayone Stycos observed that “as a field with its own body of interrelated concepts, techniques, journals and professional associations, demography is clearly a discipline” (1987, p. 616). Caldwell also reached this conclusion, but more for methodological reasons: “Demography will remain a distinct discipline because of its approach: its demand that conclusions be in keeping with observable and testable data in the real world, that these data be used as shrewdly as possible to elicit their real meanings, and that the study should be representative of sizable or significant and definable populations” (1996, p. 333).

Borrie, W. D. 1973. The Place of Demography in the Development of the Social Sciences. In International Population Conference, Liege, 1973, 73–93. Liege, Belgium: International Union for the Scientific Study of Population.

Caldwell, John C. 1996. Demography and Social Science. Population Studies 50: 305–333.

Davis, Kingsley. 1948. Human Society. New York: Macmillan.

Hauser, Philip M., and Otis Dudley Duncan. 1959. The Nature of Demography. In The Study of Population: An Inventory and Appraisal, ed. Philip M. Hauser and Otis Dudley Duncan, 29–44. Chicago: University of Chicago Press.

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Demographics

Encyclopedia of Small Business
COPYRIGHT 2007 Thomson Gale

Demographics

Demography is the statistical study of populations; the roots of the word come from the Greek for people (demos ) and picture (graphy ). Demographics, thus, are pictures of the people derived from statistics. The largest single, consistent collection of data on the population is the U.S. census conducted every ten years under the auspices of the U.S. Census Bureau. The Bureau also collects partial data every year, published as "population estimates." The census itself is at least theoretically a 100 percent count, although controversies about "under-counted" elements of the population break out every decade. This national count covers numbers, gender, age, family relationships, ethnicity and/or race, location, income, occupation, and data on housing patterns. The geographical coverage is down to the census tract level (just a few blocks in extent), so that, for census years, anyway, data can be obtained down to the zip-code level.

All demographics are ultimately based on the census, although the data are extended by many other surveys, many conducted by government agencies. The U.S. Department of Health and Human Services (HHS), for instance, tracks health issues; U.S. Department of Labor follows employment trends; U.S. Department of Education captures data on educational levels; U.S. Department of Agriculture collects and publishes data on farmers; and state vehicle registration offices collect data on driving. And so on.

Added to this are many, many private surveys which attempt to track consumer preferences, buying habits, attitudes, opinions, and so on ad infinitum. The best-known private survey is probably the TV-rating service provided by Nielsen Media Research. People who use discount cards at major grocery or other retail stores are supplying demographic data every time they purchase something. Every subscriber to any kind of print publication is generating demographic information for the publisher—which the publisher uses to set advertising rates. In the mid-2000s the Internet has become a major engine for collecting demographic information if the user bothers to fill out brief questionnaires in which he or she supplies a home address. That home address—plus demographic data from the census—reveal much about the person filling in the boxes: his or her likely ethnicity, age, income, and more. The values obtained are approximate because the census does not reveal individual household data, but people with similar profiles tend to live together.

It is simply to state the obvious that in the modern American culture data collection in some form or another accompanies most commercial transactions done using credit cards. Vast amounts of information come to be stored in countless computers. Techniques of "data mining" from such stores have developed over the years providing companies information better to target their customers.

The public sector (defined to include the academic) is also a major generator and user of demographic information. Health surveys, for instance, are based on doctors' patients' records. Voter registration records trigger selection of juries. HHS tracks birth and death records to generate projections of life expectancy—which in turn serve commercial purposes, e.g., life insurance. Companies and agencies can, if they make the effort, construct quite accurate "pictures" of many different aggregations of people—Superbowl attendees, large boat buyers, first-time voters, and adherents to religions or parties. Demographics is simply an aspect of modern life.

TECHNIQUES AND TRENDS

Extensive collection of demographic data by virtually all larger institutions is both necessitated and motivated by a mass culture. In contrast to Colonial times when sellers knew their customers and principals knew their students, information could be left to ordinary human memory. The gradual evolution of very large institutions far removed from what we are pleased to call "the action," the actual interchange between people, has produced disconnects between decision makers and their constituencies.

The costs of collecting precise demographic data are high, even when in part subsidized by public services like the census. A major trend in this field is to automate data collection using computers and incentives. Free information on the Internet (but you must register ) or small discounts available when you use a discount card (but you had to tell something about yourself to get it) are two examples of incentives provided. The data collected are then consulted using specialized analytical software the reports from which are integrated into the decision stream.

Indirect marketing by mail or advertising are notoriously hit and miss. Producing ever better profiles of people who watch a show or people who live in a zip code helps advertisers and marketers to pinpoint the right "venue" on which to spend money to reach its most desired audience, be that that the "young" or the "young-at-heart."

The high costs of mass marketing can be made more effective by ever more precisely targeted marketing aimed at pre-qualified buyers. But for this method to work, it must remain automated. The highest costs are associated with actual contact between a researcher and a would-be customer; and for this contact to yield any meaningful results, it will require 20 minutes of interaction. Such contacts are only made with tiny samples.

THE PRIVACY DEBATE

The vast stocks of demographic data held by many thousands of institutions in easily searchable and correlatable forms has spawned a debate about privacy. The issue has heated up since Internet browsing became widespread and techniques were developed, through search engines or Internet portals, to track and to record the interests of a user. Articles appear at regular intervals in which a savvy investigator shows just how rapidly he or she can determine intimate details about the life of a celebrity. The issue will continue to evolve, of course. The simple fact is that privacy is attainable, if attainable at all, only by opting out of any and all transactions that require electronic mechanisms or filling in forms. The real protection consumers have is that the exploitation of the data by marketer or others is costly and difficult. As anyone leafing through the day's mail can attest, despite a vast amount of information out there, many people sending letters to us are aiming at an altogether wrong profile.

SMALL BUSINESS AND DEMOGRAPHICS

It is something of a truism that the business close to its clientele can do without fancy demographics to reach its market. Some small businesses, of course, are in business precisely to provide such data to their customers. They will, therefore, be very knowledgeable about demographics; they are still not likely to use such data to reach their markets. Other small businesses may be servicing a national market through a Web site, for instance, and, through that web site, may have access to data on their customers that might be exploitable. For most small businesses thinking of turning demographic data to good use for expansion, through a direct mailing for instance, might explore the field by using the services of an advertising agency. The agency will have knowledge of and access to much of the tooling required, including existing and well-honed mailing lists.

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Demography

New Dictionary of the History of Ideas
COPYRIGHT 2005 The Gale Group, Inc.

DEMOGRAPHY.

Demography is the study of human population and its changes due to deaths, births, marriages and divorces, and migration. The term demos denotes people in Greek—the term demography literally means the systematic study of people. In the early twenty-first century the discipline encompasses a broad array of subject matters, covering, among others, economic, social, public health, and political issues. This entry will provide a brief overview of the uses of demographic data and key trends.

Contemporary demographers focus on two broad areas. The first is the size, composition, and characteristics of populations. The second focus is on processes that influence population change. Demographers need data to conduct analyses: censuses, surveys, and civil and vital registrations are sources of population-related information. Censuses collect data or information at the household level and are conducted at regular intervals. Surveys based on scientific sampling principles are conducted as needed for a variety of purposes, but participation by individuals is voluntary. The registration of births, deaths, marriages, and divorces, along with mandatory reporting requirements for communicable diseases or for residence changes, serve as excellent sources of data on fertility, mortality, nuptiality, and migration. An additional source of population data includes estimations, which are increasingly sophisticated calculations based on information not directly related to the sources listed here.

In addition to the size and spatial aspects of settlement, demographers examine and analyze factors related to the composition of populations, namely age groupings and race/ethnic and gender distributions. Characteristics of populations, such
as education and economic status, are also studied. Generally these factors are examined from a single point in time or cross-sectional perspective as well as in reference to dynamic changing processes (longitudinal).

Data on the size, composition, and characteristics of populations are used for a variety of public and private purposes. Drawing political boundaries for elections, determining commercial investment decisions, and assessing the prevalence of health problems are three examples of uses of demographic data. For example, the number of congressional districts in the United States has remained constant at 435 for nearly a century, despite a tripling of the nation's population. The allocation of congressional districts is based on a state's share of the national population.

Another example of the use of demographic analyses occurs when states, counties, and cities make decisions about infrastructure investments, such as the location of new fire stations, schools, and public libraries. Furthermore, private firms use population information such as education level and incomes to target households for marketing purposes or to estimate the need for commercial services. Demographic data are also used to calculate rates of prevalence of disease in order to assess the magnitude and the need for intervention. The incidence of communicable disease—for example, tuberculosis—is standardized (e.g., per 10,000 population), facilitating comparisons across administrative boundaries and helping to focus attention on health disparities between areas and population subgroups.

Demography addresses the processes that change populations. Three related factors affect population change:

Fertility, which measures the average number of children born to a woman (or populations) during child-bearing ages;

Mortality, which is the process by which deaths occur in populations; and

Migration, which is the movement of individuals or groups that involves a permanent or semipermanent change of residence across administrative and political boundaries, that is, across county, state, and national boundaries.

The twentieth century was characterized by what has been termed a demographic transition, in which mortality rates dropped dramatically due to advances in sanitation, access to health care, rapid socioeconomic changes, including a change in the status of women and altered attitudes toward contraception. The reduction in mortality was followed by declines in fertility rates. The fertility decline was evident in Europe, North America, and Oceania throughout the latter part of the twentieth century, with fertility rates at or below the replacement level of 2.1 children per women. By the year 2000, most Asian and Latin American countries had entered a transition toward lower fertility, and by the start of the twenty-first century, some low-fertility countries had adopted policies to reverse the declines. Many of the countries that had not shown fertility declines were located in sub-Saharan Africa. In addition to high infant mortality rates, mortality among the working-age population in Africa was also high as a result of the Acquired Immune Deficiency Syndrome (AIDS) epidemic, which was having a profound and detrimental impact.

By the early twenty-first century, the population aged sixty-five and above in low-fertility countries was increasing at a much faster rate than those of lower age ranges because of increased life expectancy combined with low birth rates. Since older populations typically need more health care along with support during retirement, increases in elderly populations put a strain on health care, social security, and pension systems. The aging population had a significant impact on health care systems and workforce recruitment and training and initiated a debate on how to support an aging population through publicly funded social security schemes. These debates occurred at a time when the size of the younger working population was shrinking.

In low-fertility countries, immigration mediated the impact of fertility declines. In North America and Oceania, large-scale immigration began in the nineteenth century, and net migration became a significant and increasing component of the population increase by the early twenty-first century. Other Western countries have had a history of emigration, that is, an outflow of people rather than immigration. But from the 1960s onward, an influx of African and Asian immigrants to Europe, both legal and illegal, gave rise to social and political pressures.

While fertility levels are declining in Asia, Latin America, and the Middle East, population size will continue to grow for the foreseeable future because large proportions of the population are in the younger reproductive ages. Emigration plays only a small role in reducing population growth in these regions. The challenge for many of these countries is to provide education, workforce training, and employment to their predominantly young populations, and failure to meet these needs may lead to political instability and sometimes acts of violence. Most spheres of human activity—political, social, and economic—now involve consideration of the size, composition, and characteristics of the population. This is unlikely to change as nations confront the issues discussed here.

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demography

demography The study of human populations, their growth and decline, due to changing patterns of migration, fertility and mortality, and characteristics such as the sex-ratio, dependency ratio, and age-structure. The subject is sometimes divided for further elucidation into ‘formal demography’, meaning the formal statistical analysis of population parameters and dynamics, and ‘population studies’, the wider investigation of the causes and consequences of population structures and change. It is in the latter area that many demographers have interests which overlap with those of sociologists, and in much sociological investigation demographic analysis forms an important component in the description and understanding of human societies.

The methodology consists of analysis of databases of official statistics from births, deaths, and marriage registration, and from population censuses. Demographers seek ultimately to produce population projections, that is, forecasts not only of the size of the population over coming decades, but also its changing age-structure, which can be important for social policy and labour-market policy. For example, if the dependent population (children under school-leaving age and people over retirement age) is growing relative to the population of working age which has to support it financially, there may be major implications for taxation, social insurance, and fiscal policy. If the population of working age is declining in absolute numbers, there may be a case for government policy to encourage a larger percentage (of women especially) to enter employment. Thus demographic statistics and analyses provide the essential underpinning for many other types of study. For this reason population censuses were the very first type of systematic social enquiry to be developed.

Analyses of vital statistics do, however, have their limitations. In particular, they cannot supply information on the motivations, value-systems, or aims and preferences underlying changes in the birth-rate, which is a key factor in population growth. In recent years, there have been concerted efforts to develop and carry out interview surveys on fertility orientations and behaviour. These cover issues such as the preferred number of children in a family, the effects of household income and women's employment on their fertility, attitudes to contraception and its use—all factors affecting the timing and spacing of births. The World Fertility Survey in the 1970s established standards of data collection and analysis for an important addition to the demographer's repertoire of data sources and research analyses. See also HISTORICAL DEMOGRAPHY; SOCIAL DEMOGRAPHY.

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demography

The Columbia Encyclopedia, 6th ed.

Copyright The Columbia University Press

demography (dĬmŏg´rəfē), science of human population. Demography represents a fundamental approach to the understanding of human society. Its primary tasks are to ascertain the number of people in a given area, to determine what change that number represents from a previous census, to explain the change, and to estimate the future trends of population changes. The demographer also traces the origins of population changes and studies their impact. Demographers compile and analyze data that are useful for understanding various social systems and for establishing public policy in such areas as housing, education, and unemployment.

See K. Davis, ed., Demography Series (20 vol., 1976).

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demography

de·mog·ra·phy
/ diˈmägrəfē/
•
n.
the study of statistics such as births, deaths, income, or the incidence of disease, which illustrate the changing structure of human populations. ∎
the composition of a particular human population:
Europe's demography.DERIVATIVES:de·mog·ra·pher
/ -fər/ n.

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demography

demography Term introduced (1855) by Achille Guillard for the scientific study of human populations and their changes, movements, size, distribution and structure. The primary sources of data are the census and vital statistics. Demographic methods are used for gauging and anticipating public needs.

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demography

demography The statistical study of the size and structure (e.g. with regard to age or sex distribution) of populations and of changes within them. The word is derived from the Greek demos, meaning ‘people’ and graphe, ‘writing’.

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demography

demography The statistical study of the size and structure (e.g. with regard to age or sex distribution) of populations and of changes within them. The word is derived from the Greek demos, ‘people’, and graphe, ‘writing’.

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